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| author | Alexey Gladkov <gladkov.alexey@gmail.com> | 2020-05-18 20:07:38 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-05-19 07:07:50 -0500 |
| commit | 9d78edeaec759f997c303f286ecd39daee166f2a (patch) | |
| tree | 2325279bb24196709e59a506cbf4f346c1e69a2b /net/ipv6 | |
| parent | 2dd8083f6d8acd1371ccabedef1c9f1ad272a90d (diff) | |
| download | linux-9d78edeaec759f997c303f286ecd39daee166f2a.tar.gz linux-9d78edeaec759f997c303f286ecd39daee166f2a.tar.bz2 linux-9d78edeaec759f997c303f286ecd39daee166f2a.zip | |
proc: proc_pid_ns takes super_block as an argument
syzbot found that
touch /proc/testfile
causes NULL pointer dereference at tomoyo_get_local_path()
because inode of the dentry is NULL.
Before c59f415a7cb6, Tomoyo received pid_ns from proc's s_fs_info
directly. Since proc_pid_ns() can only work with inode, using it in
the tomoyo_get_local_path() was wrong.
To avoid creating more functions for getting proc_ns, change the
argument type of the proc_pid_ns() function. Then, Tomoyo can use
the existing super_block to get pid_ns.
Link: https://lkml.kernel.org/r/0000000000002f0c7505a5b0e04c@google.com
Link: https://lkml.kernel.org/r/20200518180738.2939611-1-gladkov.alexey@gmail.com
Reported-by: syzbot+c1af344512918c61362c@syzkaller.appspotmail.com
Fixes: c59f415a7cb6 ("Use proc_pid_ns() to get pid_namespace from the proc superblock")
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_flowlabel.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index d64b83e85642..ce4fbba4acce 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -779,7 +779,7 @@ static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos) { struct ip6fl_iter_state *state = ip6fl_seq_private(seq); - state->pid_ns = proc_pid_ns(file_inode(seq->file)); + state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb); rcu_read_lock_bh(); return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; |